1. Field of the Invention
The present invention relates to an aperture control device that drives an aperture of a lens and a camera that includes the aperture control device.
2. Description of Related Art
An aperture control device used for a camera and the like is disclosed in Japanese Laid Open Patent Publication No. H11-282043. The aperture control device increases driving amount of an aperture driving lever on the camera by a gear train and detects, as the driving amount of the aperture driving lever, a gear rotation speed by a photo interrupter and the like. When the detected value is a predetermined value, the aperture control device puts a brake on the gear train to stop the gear train and the aperture driving lever that is interlocked with the gear train so as to obtain an intended aperture value.
A conventional aperture control device puts a brake on a gear train by engaging a pawl to a ratchet wheel of the gear train. An instruction for starting engaging the pawl is issued, taking into account the time between beginning of the movement of the pawl and engaging of the pawl to a ratchet wheel. However, if the pawl abuts against a tooth top part of the ratchet wheel, the pawl bounces and causes a stop phase of the gear train to be shifted. IN this case, a desired aperture value may not be obtained.